Final answer:
A follow-up ultrasound after applying a Pavlik harness for developmental dysplasia of the hip is typically recommended 1 to 2 weeks later to evaluate the position of the hip joint and treatment effectiveness.
Step-by-step explanation:
After applying a Pavlik harness for the treatment of developmental dysplasia of the hip (DDH) in infants, a follow-up ultrasound is generally recommended to be performed after 1 to 2 weeks. This waiting period allows for initial adjustment and soft tissue relaxation, which can contribute to the stabilization of the hip. The subsequent ultrasound is used to assess the position of the hip joint and the effectiveness of the harness in maintaining reduction. The exact timing can vary depending on the protocol of the treating physician and the specific needs of the patient.